/*
 * Copyright 2012-2021 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.boot.context.event;

import org.springframework.boot.ConfigurableBootstrapContext;
import org.springframework.boot.SpringApplication;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationListener;
import org.springframework.core.env.Environment;

/**
 * 事件在 {@link SpringApplication} 启动后尽可能早地发布——
 * 在 {@link Environment} 或 {@link ApplicationContext} 可用之前，
 * 但在 {@link ApplicationListener} 注册之后。
 * 事件的来源是 {@link SpringApplication} 本身，
 * 但请注意在此早期阶段过度使用其内部状态，因为它可能在生命周期后期被修改。
 *
 * @author Phillip Webb
 * @author Madhura Bhave
 * @since 1.5.0
 */
@SuppressWarnings("serial")
public class ApplicationStartingEvent extends SpringApplicationEvent {

	private final ConfigurableBootstrapContext bootstrapContext;

	/**
	 * 创建一个新的 {@link ApplicationStartingEvent} 实例。
	 * @param bootstrapContext 启动上下文
	 * @param application 当前应用
	 * @param args 应用运行的参数
	 */
	public ApplicationStartingEvent(ConfigurableBootstrapContext bootstrapContext, SpringApplication application,
			String[] args) {
		super(application, args);
		this.bootstrapContext = bootstrapContext;
	}

	/**
	 * 返回启动上下文。
	 * @return 启动上下文
	 * @since 2.4.0
	 */
	public ConfigurableBootstrapContext getBootstrapContext() {
		return this.bootstrapContext;
	}

}
